U.S. officials promise to create new policies for suspended 'chimera' research

Federal officials promised on Friday to quickly create new policies to govern a promising field of stem cell research that is now in limbo because of an abrupt suspension of funding by the Obama administration.

While offering no guarantee of renewed support, "the intent is to move forward," said Carrie D. Wolinetz, associate director for science policy at the National Institutes of Health, at a workshop to review the state of the research, which strives to grow human organs in animals, called "chimeras," after the hybrid creatures in Greek mythology.

"We can provide a purposeful path that supports research, rather than impedes it through further delay," she said.

The meeting was held a day after a critical letter by Stanford scientists in the journal Science warned that the funding moratorium imposed by NIH in September could delay discoveries in the field.

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Once major technical hurdles are overcome, chimera research could lead to improved drug testing and an endless supply of organs for transplantation, scientists testified at NIH headquarters in Bethesda, Maryland.

At Stanford University, where a research oversight body weighs the risks and benefits before authorizing research, "we approve research because we think it is an opportunity to relieve human suffering," Hank Greely of the Center for Law and Biosciences told NIH. "But the solution can't be carved in stone. ... It needs to be a process."

While the NIH decides how to proceed, a chimera-based project is suspended in the lab of Juan Carlos Izpisa Belmonte, a developmental biologist at the Salk Institute for Biological Studies in San Diego. He has been injecting a new type of human stem cell into the embryos of genetically modified pigs, which start early development of humanlike heart and pancreatic tissue.

"My application is on hold," Belmonte said. "What is the reason for these regulations, so we can address the concerns and the problem? We don't know where this is coming from. What has happened in the last years? The mechanism we have appears to be working.

"Every 30 seconds, a patient dies from diseases that could be treated with tissue replacement," he added.

At Stanford, the moratorium means that stem cell biologist Hiromitsu Nakauchi will continue to rely on state, not federal, support. He is planning to inject human stem cells into pig embryos -- genetically engineered to not grow their own pancreas -- in an effort to learn more about diabetes.

"Now we are more or less ready to do the experiment we envision," he told the NIH.

Already he has grown a mouse pancreas in a rat and transplanted it back into a mouse -- where it released the hormones insulin and glucagon into the animal's bloodstream, helping regulate the animal's glucose levels.

"We need to make organs from stem cells," said Nakauchi, citing the shortage of donors, the problem of rejection and high medical costs of organ failure.

"All of these issues can be resolved by generating functional from patients' own stem cells," he said. "This is one of the most urgent fields in regenerative medicine."

There are still obstacles to successful science, the scientists said. The animals may reject human cells. Animals and humans have different lengths of pregnancy. Organs develop at different speeds. They are different sizes. And cells don't like to be mixed, so they compete with each other.

"Even though the idea of generating cells tissue and in animal host for transplantation is very appealing, we are far away from that," said Salk's Belmonte.

Ethical problems can be prevented by taking practical steps, such as not allowing juvenile animals to grow and reproduce. And if we don't want animals to have certain human , researchers could genetically manipulate cells so they are incapable of maturing into those , scientists said.

"You seem to think the issues are all put to bed," countered attorney ad bioethicist David Resnick of the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina.

"Science moves fast. The prospect of an intelligent mouse, stuck in a lab screaming 'I want to get out!' is very troubling to people," he said. "There is psychic suffering, not just physical suffering."

The scientific presentations will help NIH decide its next step, Wolinetz said. "Is our existing framework sufficient?" she asked. "Or does it need improvement?